add saturation option

README.md

@@ -35,7 +35,13 @@ The plugin provides the `LEDBreatheEffect` object, which has a single property:
 
 > The hue of the breathe effect.
 >
-> Defaults to 170.
+> Defaults to 170, a blue hue.
+
+### `.saturation`
+
+> The color saturation of the breathe effect.
+>
+> Defaults to 255, the maximum.
 
 ## Dependencies
 

src/Kaleidoscope-LEDEffect-Breathe.cpp

@@ -2,7 +2,7 @@
 
 namespace kaleidoscope {
 void LEDBreatheEffect::update(void) {
-  cRGB color = breath_compute(hue);
+  cRGB color = breath_compute(hue, saturation);
   ::LEDControl.set_all_leds_to(color);
 }
 }

src/Kaleidoscope-LEDEffect-Breathe.h

@@ -9,6 +9,7 @@ class LEDBreatheEffect : public LEDMode {
   LEDBreatheEffect(void) {}
 
   uint8_t hue = 170;
+  uint8_t saturation = 255;
 
  protected:
   void update(void) final;